Set value of List field of a node with multiple values

Question

I'm attempting to programmatically generate nodes of a custom content type from a form plugin. For most fields I don't have any trouble at all. For example for the title field I can set the value like so.

$node->title->value = t('My title');
$node->save();

However there is also a list(text) field that allows for multiple values. And I'm not sure how to go about saving values of field with multiple values. I'm assuming if there was only one value allowed I could do it just like I set the title in the previous example, but how do I deal with it when the field is an array? As a test I performed a die statement of the field on a node that already had values in that field to take a look at what it looks like and this was generated:

Array ( [0] => Array ( [value] => test_3 ) [1] => Array ( [value] => test_4 ) ) 1

But I'm not sure what to do with that. How would I set the field value of a list field with multiple values allowed?

Answer 1

You can replace the complete content of a field by assigning an array:

$node->field_multivalue = [
  ['value' => '1'],
  ['value' => '2'],
  ['value' => '3'],
];

If you want add another value to the field you can use the field like a php array:

$node->field_multivalue[] = ['value' => '4'];

You can omit the main property of a field:

$node->field_multivalue[] = '5';

Now you have 5 values in the field.